Many pet food companies use the cheapest ingredients they can find. Whether it comes from dead, diseased, road kill, or euthanized pets from shelters. These ingredients are not suitable for human consumption. If you won't eat it, why should your dog! Most pet foods contain 4-D ingredients. 4-D is meat and by-products that have been derived from animals that were rejected by food inspectors who classified the animals as not fit for human consumption because they were “Dead, Dying, Disabled or Diseased” at the time of inspection. Any chemicals that existed within that animal would still be inside of it when dead. Meat by-products are nothing more than slaughterhouse waste; waste that's been banned for use in human food and then sold to the pet food industry. It’s what’s left over after the slaughter and classified as inedible waste, unfit for human consumption. With dry foods, the ingredients are cooked twice. First during rendering and again in the extruder.